Tag Archives: Polaris

In less than a week, people all over the country, including right here at our museum, will be celebrating Halloween. Perhaps your workplaces and schools are already festooned with ghosts, skeletons, graveyards, and the like. If you stop and think about it, you may wonder just how it is that we came to celebrate by trying to disguise ourselves or by trying to frighten people. Is this a trick or a treat?

The short answer as to why we celebrate this time of year with images of death is that we are in the middle of autumn, the season when nature itself is dying. To fully understand why we celebrate Halloween when we do, we must fully understand the seasons.

Earth orbits the Sun with its axis pointed at the North Star, Polaris. As a result, its axis is tilted by about 23.5 degrees with respect to its orbital plane. This tilt, combined with Earth’s revolution around the Sun, causes the seasons. If the North Pole leans towards the Sun, the Sun is higher in our sky and we get more direct sunlight. Also, daytime is longer than nighttime. As the North Pole begins to tilt away fron the Sun, the Sun appears lower and lower across the sky, and daytime gets shorter and shorter. Eventually, the slanted-in solar rays and short days bring about winter. Very cold air masses form in the darkened Arctic and begin to move south, some of which can even reach Houston.

Keep in mind that the Earth’s axis does not tilt back and forth; it points at Polaris the whole time. In June, the North Pole is leaning towards the Sun, but by December, the Earth’s motion has carried it to the other side of the Sun. The North Pole, still tilting the same way, now leans away from the Sun.

A common misconception is that the Earth is closer to the Sun in summer and more distant in winter, and that is what causes our seasons. In fact, Earth’s perihelion (closest approach to the Sun) occurs just after the new year (January 1-4), while aphelion (greatest distance from the Sun) occurs around the 4th of July. Earth’s orbit is an ellipse, but the Earth-Sun distance does not change by enough to affect our seasons.

In the cycle of seasons, there are four points of note. At the March equinox, neither pole is tilted toward the Sun and the Sun is directly overhead at the equator. The is the vernal (spring) equinox for us and the autumnal (fall) equinox for folks south of the equator. At the June solstice, the North Pole is tilted as much as possible towards the Sun, and the Sun is overhead at 23.5 degrees North (the Tropic of Cancer). This is the summer solstice for us and the winter solstice in the Southern Hemisphere. At the September equinox, once again neither pole tilts toward the Sun, and the Sun is again overhead at the equator. This is our fall equinox and their spring equinox. At the December solstice, the North Pole is tilted as much as possible away from the Sun, and the Sun is overhead at 23.5 degrees South (the Tropic of Capricorn). This is the winter solstice for us and the summer solstice below the equator.

We generally think of these points as the beginning of spring, summer, fall, and winter, but it doesn’t have to be that way. After all, nothing magically happens with our weather on these dates. We could just as well consider these points the midpoints of each season. In that case, the seasons would begin and end at points roughly halfway between the equinoxes and solstices, in early February, May, August, and November. If the equinoxes and solstices are ‘quarter days,’ the points halfway between them become the ‘cross-quarter days.’

The ancient Celts of Europe appear to have divided their year in precisely that way. Gauls living in what is now France used a calendar of twelve lunar months with a 13th month added every 2.5 years (similar to the Hebrew calendar today). Their two most significant months were Gamonios (lunar month corresponding to April/May ), which began the summer half of the year, and Samonios (lunar month corresponding to October/November) which began the winter half of the year. Julius Caesar noted that daytime followed nighttime in Celtic days. By extension, the dark (winter) half of the Celtic year preceded the light (summer) half, making Samonios the start of their new year.

The Celts in the British Isles (Irish and Scots) also had festivals aligned with the cross-quarter days. In early February was Imbolc (or St. Brigid’s day). Weather predicting traditions of this day are preserved in our current Groundhog Day. Traditional May Day celebrations are similar to those of the Celtic Beltane. Lughnasadh, in early August, marked the start of the harvest.

The most important, though, was Samhain (pronounced ’sah win’, not ‘Sam Hane’, due to rules of Gaelic spelling), in early November. This three-day festival marked the beginning of the winter half of the year and the start of the whole year, like Gaulish Samonios. It was the close of the harvest opened at Lughnasagh, and the time for culling excess livestock. At this time, the veil between the living and the world of the dead was considered thinner than usual, and people looked forward to meeting and communing with ancestors and relatives who had died. A ‘dumb supper‘ was set aside for departed relatives. To scare away unwanted spirits, people dressed in frightening garb. Note that these spirits were considered unpredictable and possibly mischievous because they were not the familiar ancestors–not because they were particularly evil. Divination was also practiced at this time, as people sought to predict whom they would marry or how many children they would have.

Doing the math, you’ve probably figured out that Halloween is not quite halfway from the equinox (September 22) to the solstice (December 21). But remember, the Celts used a lunar calendar. They celebrated their festivals on a certain phase of the Moon, possibly full moon, occurring nearest the cross-quarter day. Upon the adoption of the Julian calendar, which was not strictly lunar, the festivals were moved to the beginning of February, May, August, and November, although this meant they were no longer exactly on the cross-quarter days.

In the eighth century AD, Pope Gregory III moved the church’s commemoration of the souls in heaven (All Saints’ Day) from May 13 to November 1. Another name for All Saints’ Day is All Hallows Day. (’Hallow’ is an older term for ’sanctify’ or ‘make holy.’ Think of ‘…hallowed be thy name’ from the Lord’s Prayer). The next day became All Souls’ Day. The day before All Hallows Day or All Saints’ Day is All Hallows Eve, or Halloween. The traditions of Samhain, with its similar focus on honoring the dearly departed, were a natural fit for All Hallows Day and All Hallows Eve.

Halloween, then, is ultimately just one expression of the human need to come to terms with death as a natural occurence and to honor those who have gone before. In the season of the fall of the leaf, with the Sun taking a slightly lower path across the sky each day, the natural world is going through its own ‘death,’ providing a perfect context for our own activities. We can therefore think of Halloween itself as a treat, not a trick.

On Thursday, June 19, we commemorated the freedom of slaves in Texas on Juneteenth. This day has become even more important for me since I learned that at least 15 of my 16 great-great-grand-parents were in bondage right here in southeast Texas in 1865. Nearly all of my ancestors, then, learned of their freedom on June 19, 1865, when General Gordon Granger of the US Army arrived in Galveston and officially informed Texans that the Civil War, and thus slavery, was over.

June, then, is an excellent time to reflect on how the sky helped guide many slaves from bondage to freedom. Slaves who wanted to escape needed to work their way north to the Ohio River to link up with a network of safe houses known as the “Underground Railroad.” After a stringent Fugitive Slave Law was passed in 1850, slaves needed to make it all the way to Canada to attain their freedom. Slaves here in Texas would run south to Mexico. Fugitive slaves ran at night to give themselves the longest possible head start on slave catchers, who operated in daytime. Fortunately for them, the Earth’s axis points almost right at Polaris, the North Star, making it extremely easy to find one’s direction at night. Runaway slaves had only to ‘Follow the Drinking Gourd‘–the Big Dipper– to the North Star, and they could be on their way.

No, Polaris is not exactly at the Celestial Pole (the point in the sky directly above the North Pole), but it is off by less than 3/4 of a degree. By way of comparison, your pinky held at arm’s length blocks about one degree. This is too small an ‘error’ for us to notice with our bare eyes. Thus, as Earth spins and most stars rise and set, we see the North Star in the same spot all night long, every night of the year, marking north more accurately than a compass does.

Contrary to widespread opinion, the North Star is not the brightest. However, it does far outshine all stars in its general area. It is part of the generally dim constellation Ursa Minor (which Americans call the Little Dipper), and therefore easily stands out. Polaris was thus easy to find and always there to guide slaves north to the Ohio River, and then on to Canada. Without Polaris, there would be no way to clearly mark north at night.

This is a stroke of pure luck for us–nothing requires a star visible to the naked eye near the Celestial Pole. The South Pole, for example, points roughly at a star 100 times too dim to be seen with the unaided eye. What’s more, the Earth wobbles as is spins. (Any spinning object must wobble unless it is completely in isolation with no forces acting on it.)

With the Moon acting as a counterweight, the Earth’s wobble is an orderly precession; the Celestial Pole describes an apparent circle on the sky once every 26,000 years. Polaris’ position as North Star, then, is temporary. Many millennia from now, our distant descendants will need some other way of marking north, as Polaris will be much father from the Pole.

Ancient Phoenicians sailing the Mediterranean used entire Ursa Minor constellation as a guide, as Polaris alone was not close enough to the Pole to be useful. Builders of the Egyptian pyramids used another star altogether. For most of Earth’s history, there has been no bright star at either Celestial Pole.

What good fortune, then, that is these last millennia we’ve had a star to help bring sailors to shore and bondsmen to liberty. What about those who didn’t want to go north? Facing north puts east on your right, west on your left, and south at your back. Marking one direction, then, helps us identify them all. Texan slaves running to Mexico would have found the North Star just as useful as did slaves running to Canada. Estimates vary as to how many slaves were able to escape along the Underground Railroad, but they generally range from thousands to tens of thousands. Frederick Douglass named his anti-slavery newspaper The North Starafter the star that brought so many ex-slaves to freedom.

Tonight the Big Dipper, the slaves’ Drinking Gourd, is high above the North Star at dusk and therefore easy to see. Stand with the point of sunset on your left to face north. Then look for seven stars of roughly equal brightness about 2/3 of the way up.

At dusk in June, the Dipper is oriented with the handle pointing more or less up. The three stars in the handle are highest, with the four bowl stars to their lower left. The two bowl stars farthest from the handle point directly at the North Star, Polaris. These are the stars that guided thousands to freedom.

From our southerly latitude here in Houston, the Big Dipper is hard to see on late fall and early winter evenings, but is up the rest of the year. You can see the North Star, on the other hand, every night of the year in the same position. Each time you find north with the stars, I invite you to reflect on how finding Polaris helped so many to change their lives.